Tantalum-solid electrolyte capacitors can, for example, be used in portable applications such as mobile telephones, laptops, palmtops, camcorders and the like in part because of their energy storage density. The main constituents of these Ta-solid electrolyte capacitors are Ta anodes. Increasingly thinner portable electronic devices are desired despite an increasing integration density of the components. Such anodes are usually produced by pressing Ta oxide and/or niobium oxide powder onto thin Ta sheets, followed by sintering. This conventional pressing-on of Ta powder does not, however, allow large aspect ratios to be produced, i.e., anodes for flat Ta capacitors having a low construction height cannot be produced in this way.
Tantalum anodes produced by printing of a Ta paste onto a Ta foil as substrate and subsequent binder removal/sintering often display severe distortion of the Ta substrate after sintering. The anode is then no longer flat and firstly cannot be processed as well and, secondly, the effective height of the anode is greater than when no distortion has occurred, i.e., volume which could be occupied by active composition is not used. Relatively high-capacitance tantalum powders and NbO powders, in particular, promote distortion and thin Ta foils, in particular, experience particularly severe distortion. Thicker Ta foils or sheets having a thickness of more than 100 microns are therefore used according to the prior art. A consequence of this is that stencil-printed anodes have an unfavorable ratio (sintered anode body) to passive Ta composition (Ta sheet substrate) and therefore have higher materials costs compared to pressed anodes.